Motor driving device

ABSTRACT

A motor driving device for driving a motor includes a motor driver, a speed control loop, a current control loop, and an arithmetic selecting module. The motor driver provides a current signal for the motor to output a speed signal. The speed control loop receiving the speed signal and a speed command, includes a first selector and two first arithmetic modules. The current control loop receiving the current signal, includes a second selector and two second arithmetic modules. The arithmetic selecting module outputs a first select command and a second select command to select an arithmetic module of the speed control loop and the current control loop correspondingly. The speed control loop provides a current command for the current control loop and the arithmetic selecting module. The current control loop provides a control signal for the motor driver to adjust the current signal thereby to adjust the speed signal.

BACKGROUND

1. Technical Field

The present disclosure relates to driving devices and, particularly, toa motor driving device.

2. Description of the Related Art

A general motor driving device is only capable of using a certain sortof arithmetic control process, such as proportional-integral (PI)arithmetic, proportional-derivative (PD) arithmetic,proportional-integral-derivative (PID) arithmetic, or fuzzy arithmeticand so on, to drive a motor. Different arithmetic control processcontrols different driving performance of the motor. For example, the PIarithmetic controls stable performance of the motor, and the PDarithmetic controls dynamic performance of the motor. However,invariable arithmetic control process is not capable of achieving asatisfying performance of the motor when load or operation environmentof the motor is changed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of an exemplary embodiment of a motor drivingdevice.

FIG. 2 is a block diagram of another exemplary embodiment of a motordriving device.

DETAILED DESCRIPTION

Referring to FIG. 1, an exemplary embodiment of a motor driving device10 includes a servo system 100, an arithmetic selecting module 200, aspeed control loop 300, and a current control loop 400.

The servo system 100 includes a motor driver 101 and a motor 102. Themotor driver 101 is configured for driving the motor 102.

The arithmetic selecting module 200 includes an arithmetic selectingdiscriminator 201, a human-machine interface (HMI) 202, and an inputselecting element 203. The input selecting element 203 is configured forselectively receiving selection commands of the arithmetic discriminator201 or the HMI 202. The input selecting element 203 may be hardware,such as a single-pole double-throw (SPDT) switch, or may be software,such as a control program.

The speed control loop 300 includes a first selector 301, a firstarithmetic module 311, and a second arithmetic module 312. The firstselector 301 is configured for receiving a first selection command Sc1output from the input selecting element 203, to select a correspondingarithmetic module from the first and second arithmetic modules 311 and312 of the speed control loop 300. The first arithmetic module 311 andthe second arithmetic module 312 are configured for storing differentarithmetic control processes.

The current control loop 400 includes a second selector 401, a thirdarithmetic module 411, and a fourth arithmetic module 412. The secondselector 401 is configured for receiving a second selection command Sc2output from the input selecting element 203, to select a correspondingarithmetic module from the third and fourth arithmetic modules 411 and412 of the current control loop 400. The third arithmetic module 411 andthe fourth arithmetic module 412 are configured for storing differentarithmetic control processes. In one exemplary embodiment, the speedcontrol loop 300 and the current control loop 400 are two dataprocessing chips.

The motor driver 101 is powered to provide a current signal Is fordriving the motor 102. The motor 102 provides a speed signal Vs for thespeed control loop 300 and the arithmetic selecting discriminator 201.Meanwhile, the current signal Is is provided for the current controlloop 400 and the arithmetic selecting discriminator 201.

A speed command Vc is provided for the speed control loop 300 and thearithmetic selecting discriminator 201 when the motor driver 101 ispowered. A speed value of the speed signal Vs of the motor 102 is about0 at the beginning of powering the motor driver 101. Therefore, the HMIor the arithmetic selecting discriminator 201 can be selected manuallyor automatically via the input selecting element 203 to provide thefirst select command Sc1 for selecting an arithmetic module from thefirst and second arithmetic modules 311 and 312 of the speed controlloop 300.

When the arithmetic selecting discriminator 201 is selected to providethe first select command Sc1 for the first selector 301, the arithmeticselecting discriminator 201 compares the speed command Vc with the speedsignal Vs, and automatically selects, via the first selector 301, aarithmetic module from the first and second arithmetic modules 311 and312 of the speed control loop 300 according to a speed difference of thespeed command Vc and the speed signal Vs. For example, when the speeddifference between the speed command Vc and the speed signal Vs is equalto or more than 0 rpm but less than 200 rpm, the arithmetic selectingdiscriminator 201 provides the first select command Sc1 for the firstselector 301 to select the first arithmetic module 311; when the speeddifference between the speed command Vc and the speed signal Vs is equalto or more than 200 rpm but less than or equal to 500 rpm, thearithmetic selecting discriminator 201 provides the first select commandSc1 for the first selector 301 to select the second arithmetic module312.

The speed control loop 300 provides a current command Ic after the speedcommand Vc and the speed signal Vs are processed by the selectedarithmetic module. The current command Ic is transmitted to thearithmetic selecting discriminator 201 and the current control loop 400.

The HMI 202 or the arithmetic selecting discriminator 201 can beselected manually or automatically via the input selecting element 203to select an arithmetic module from the third and fourth arithmeticmodules 411 and 412 of the current control loop 400. When the arithmeticselecting discriminator 201 is selected to provide the second selectcommand Sc2 for the second selector 401, the arithmetic selectingdiscriminator 201 compares the current command Ic and the current signalIs, and automatically selects the arithmetic module from the third andfourth arithmetic modules 411 and 412 of the current control loop 400according to a difference of the values of the current command Ic andthe current signal Is. For example, when the difference between thecurrent command Ic and the current signal Is is equal to or more than OAbut less than 5 A, the arithmetic selecting discriminator 201 providesthe second select command Sc2 for the second selector 401 to select thethird arithmetic module 411; when the current difference between thecurrent command Ic and the current signal Is is equal to or more than 5A but less than or equal to 10 A, the arithmetic selecting discriminator201 provides the second select command Sc2 for the second selector 401to select the fourth arithmetic 412.

The current control loop 400 provides a control signal Cs for the motordriver 101 after the current command Ic and the current signal Is areprocessed by the selected arithmetic module of the current control loop400, for adjusting the current signal Is, thereby adjusting the speedsignal Vs of the motor 102.

In one exemplary embodiment, the HMI 202 can be operated to transmit thefirst select command Sc1 to select an arithmetic module from the firstand second arithmetic modules 311 and 312 of the speed control loop 300,and transmit the second select command Sc2 to select an arithmeticmodule from the third and fourth arithmetic modules 411 and 412 of thecurrent control loop 400 manually at the beginning of powering the motordriver 101. However, the disclosure is not limited thereto. Thearithmetic selecting discriminator 201 is also capable of directlytransmitting the select command Sc1 and the second select command Sc2automatically at the beginning of powering the motor driver 101.Therefore, the HMI 202 and the input selecting element 203 can beomitted in another exemplary embodiment, which is illustrated in FIG. 2.

In one exemplary embodiment, the speed control loop 300 and the currentcontrol loop 400 may each include more than two arithmetic modules. Inanother embodiment, the speed control loop 300 may include only onearithmetic module while the current control loop 400 may include morethan one arithmetic module, or vice versa.

In one exemplary embodiment, other control loops of the servo system 100can be controlled by the motor driving device 10, such as a pressurecontrol loop and a voltage control loop of the servo system 400, each ofwhich may include more than one arithmetic module storing differentarithmetic control processes.

It is to be understood, however, that even though numerouscharacteristics and advantages of the present disclosure have been setforth in the foregoing description, together with details of thestructure and function of the disclosure, the disclosure is illustrativeonly, and changes may be made in detail, especially in matters of shape,size, and arrangement of parts within the principles of the disclosureto the full extent indicated by the broad general meaning of the termsin which the appended claims are expressed.

1. A motor driving device for driving a motor, comprising: a motordriver configured for driving the motor, wherein the motor driverprovides a current signal for the motor, and the motor outputs a speedsignal; an arithmetic selecting module connected to the motor and themotor driver, and configured for receiving a speed command, the speedsignal and the current signal, and providing a first select command anda second select command; a speed control loop configured for receivingthe speed signal and the speed command, the speed control loopcomprising: at least two first arithmetic modules, wherein the at leasttwo first arithmetic modules are configured for storing differentarithmetic control processes respectively; and a first selectorconfigured for receiving the first select command, the speed signal andthe speed command, and selecting one first arithmetic module from the atleast two first arithmetic modules of the speed control loop accordingto the first select command for processing the speed command and thespeed signal; wherein the speed control loop outputs a current commandafter the speed command and the speed signal are processed by theselected first arithmetic module of the speed control loop; and acurrent control loop configured for receiving the current signal of themotor driver and the current command from the speed control loop, thecurrent control loop comprising: at least two arithmetic modules,wherein the at least two second arithmetic modules are configured forstoring different arithmetic control processes; and a second selectorconfigured for receiving the second select command, the current signaland the current command, and selecting one second arithmetic module fromthe at least two second arithmetic modules of the current control loopaccording to the second select command for processing the current signaland the current command; wherein the current control loop outputs acontrol signal for the motor driver after the current signal and thecurrent command are processed by the selected second arithmetic moduleof the current control loop, to adjust the current signal of the motordriver, therefore to adjust the speed signal of the motor.
 2. The motordriving device of claim 1, wherein the arithmetic selecting modulecomprises an arithmetic selecting discriminator configured for providingthe first select command for the first selector to select acorresponding first arithmetic module of the speed control loopaccording to a speed difference between the speed command and the speedsignal, and providing the second select command for the second selectorto select a corresponding second arithmetic module of the currentcontrol loop according to a current difference between the currentcommand and the current signal.
 3. The motor driving device of claim 1,wherein the arithmetic selecting module comprises a human-machineinterface (HMI), an arithmetic selecting discriminator, and an inputselecting element; wherein the input selecting element is configured forselecting the HMI or the arithmetic selecting discriminator to providethe first select command and the second select command for the firstselector and the second selector correspondingly; wherein the arithmeticselecting discriminator is capable of providing the first select commandfor the first selector according to a speed difference between the speedcommand and the speed signal, and providing the second select commandfor the second selector according to a current difference between thecurrent command and the current signal.
 4. A motor driving device fordriving a motor, comprising: a motor driver configured for driving themotor, wherein the motor driver provides a current signal for the motor,and the motor outputs a speed signal; an arithmetic selecting moduleconnected to the motor and the motor driver, and configured forreceiving a speed command, the speed signal and the current signal, andproviding a select command; a speed control loop configured forreceiving the speed signal and the speed command, and comprising a firstarithmetic module configured for storing a kind of arithmetic controlprocesses to process the speed signal and the speed command; wherein thespeed control loop outputs a current command after the speed signal andthe speed command are processed by the first arithmetic module of thespeed control loop; and a current control loop configured for receivingthe current signal of the motor driver and the current command from thespeed control loop, comprising: at least two second arithmetic modules,wherein the at least two arithmetic modules are configured for storingdifferent kinds of arithmetic control processes respectively; and aselector configured for receiving the select command, the current signaland the current command, and selecting one second arithmetic module fromthe at least two second arithmetic modules of the current control loopaccording to the select command for processing the current signal andthe current command; wherein the current control loop outputs a controlsignal for the motor driver after the current signal and the currentcommand are processed by the selected second arithmetic module of thecurrent control loop, to adjust the current signal of the motor driverthereby adjusting the speed signal of the motor.
 5. The motor drivingdevice of claim 4, wherein the arithmetic selecting module comprises anarithmetic selecting discriminator configured for providing the selectcommand for the selector to select a corresponding second arithmeticmodule of the current control loop according to a current differencebetween the current command and the current signal.
 6. The motor drivingdevice of claim 4, wherein the arithmetic selecting module comprises ahuman-machine interface (HMI), an arithmetic selecting discriminator,and an input selecting element; wherein the input selecting element isconfigured for selecting the HMI or the arithmetic selectingdiscriminator to provide the select command for the selector of thecurrent control loop; wherein the arithmetic selecting discriminator iscapable of providing the select command for the selector according to acurrent difference between the current command and the current signal.7. A motor driving device for driving a motor, comprising: a motordriver configured for driving the motor, wherein the motor driverprovides a current signal for the motor, and the motor outputs a speedsignal; an arithmetic selecting module connected to the motor and themotor driver, configured for receiving a speed command, the speed signaland the current signal, and providing a select command; a speed controlloop configured for receiving the speed signal and the speed command,wherein the speed control loop comprises: at least two first arithmeticmodules, wherein the at least two first arithmetic modules areconfigured for storing different kinds of arithmetic control processes;and a selector configured for receiving the select command, the speedsignal and the speed command, and selecting one first arithmetic modulefrom the at least two first arithmetic modules of the speed control loopaccording to the select command for processing the speed command and thespeed signal; wherein the speed control loop outputs a current commandafter the speed command and the speed signal are processed by a selectedfirst arithmetic module of the speed control loop; and a current controlloop configured for receiving the current signal of the motor driver andthe current command from the speed control loop, and comprising a secondarithmetic module configured for storing arithmetic control processes toprocess the current command and the current signal; wherein the currentcontrol loop outputs a control signal for the motor driver after thecurrent signal and the current command are processed by the secondarithmetic module of the current control loop, to adjust the currentsignal of the motor driver thereby adjusting the speed signal of themotor.
 8. The motor driving device of claim 7, wherein the arithmeticselecting module is an arithmetic selecting discriminator configured forproviding the select command for the selector to select an arithmeticmodule of the speed control loop according to a speed difference of thespeed command and the speed signal.
 9. The motor driving device of claim7, wherein the arithmetic selecting module comprises a human-machineinterface (HMI), an arithmetic selecting discriminator, and an inputselecting element; wherein the input selecting element is configured forselecting the HMI or the arithmetic selecting discriminator to providethe select command for the selector of the speed control loop; whereinthe arithmetic selecting discriminator is capable of providing theselect command for the selector according to a speed difference betweenthe speed command and the speed signal.